A mild aromatic propargylation reaction, employing an air- and moisture-tolerant rhenium-oxo complex ((dppm)ReOCl(3)) as a catalyst and a propargyl alcohol as the electrophile, is described. The reaction tolerates a broad range of functional groups and regioselectively affords propargylic arenas without formation of the isomeric allenyl adducts. The potential of this rhenium(V)-catalyzed reacti...

The immobilization of technetium-99 ((99)Tc) in a suitable host matrix has proven to be a challenging task for researchers in the nuclear waste community around the world. In this context, the present work reports on the solubility and retention of rhenium, a nonradioactive surrogate for (99)Tc, in a sodium borosilicate glass. Glasses containing target Re concentrations from 0 to 10,000 ppm [by...

Electrochemical deposition of rhenium-iron alloy from water-in-salt electrolytes containing a super-high concentration lithium chloride is investigated. Different techniques, including cyclic voltammetry, chronoamperometry, X-ray fluorescence, scanning electron microscope, X-Ray diffraction, and electrical measurements at cryogenic temperature are used to characterize the electrochemical system...

The synthesis and full characterization of two tetrathiafulvalene-appended azine ligands, namely 2-([2,2'-bi(1,3-dithiolylidene)]-4-yl)-6-((2,4-dinitrophenyl)hydrazono)methyl)pyridine (L1) and 5-([2,2'-bi(1,3-dithiolylidene)]-4-yl)-2-((2,4-dinitrophenyl)hydrazono)methyl)pyridine (L2) are described. The crystal structure of ligand L1 indicates that the ligand is completely planar with the presen...

A sensitive detector and pressure gauge for uranium hexafluoride in high-vacuum systems is described. Negative surface ionization of UF(6) occurs on ribbon filaments operated at temperatures too low for electron emission to be significant. The ion current measured on a cylindrical collector surrounding the filament assembly varies regularly with UF(6) pressure below 10(-3) Torr. Different filam...

This research aimed to develop new tumor targeted theranostic agents taking advantage of the similarities in coordination chemistry between technetium and rhenium. A γ-emitting radioactive isotope of technetium is commonly used in diagnostic imaging, and there are two β- emitting radioactive isotopes of rhenium that have the potential to be of use in radiotherapy. Variants of the 6-hydrazinonic...

Various cationic rhenium(I) and ruthenium(II) mono- and multinuclear complexes were successfully separated by size-exclusion chromatography (SEC), using a 50:50 (v/v) mixture of methanol and acetonitrile with CH3CO2NH4 as an eluent. The logarithms of the molecular weights were accurately linear in the distribution coefficients: for linear-shaped rhenium(I) multinuclear complexes, log M(W) = -2....

Rhenium nanocrystalline particles (Re NPs), of 2 nm size, were prepared from NH4ReO4 under mild conditions in neat alcohol. The unsupported Re NPs convert secondary and benzylic alcohols to ketones and aldehydes, respectively, through catalytic acceptorless dehydrogenation (AD). The oxidant- and acceptor-free neat dehydrogenation of alcohols to obtain dihydrogen gas is a green and atom-economic...

The binding of carbon monoxide to iron, ruthenium, rhenium, and tungsten clusters is studied by means of infrared multiple photon dissociation spectroscopy. The CO stretching mode is used to probe the interaction of the CO molecule with the metal clusters and thereby the activation of the C–O bond. CO is found to adsorb molecularly to atop positions on iron clusters. On ruthenium and rhenium cl...

Z. Naturforsch. 52 b, 231-236 (1997); received November 15, 1996 Crystal Structure, Magnetic Properties, Rare Earth Metal Rhenium Carbides, Polymeric Rhenium-Carbon Polyanions ErsReiCy, TmsRe2C7, and LusReaC? were prepared by arc-melting of the elemental compo­ nents and subsequent annealing at 800 °C. ErsRe^Cy forms only after the annealing process, whereas the other two carbides were already ...